CSEM Anomalies Co-rendered with Modern Seismic to De-risk Exploration Leads – Foz do Amazonas Brazil

Abstract

Late Cretaceous to Palaeogene deep water hydrocarbon plays identified from 2D modern seismic interpretation in Foz do Amazonas, the most northerly of the Brazilian equatorial margin basins, highlighted potentially large reserves in the unexplored deep water. At the same time, a series of resistive anomalies identified from 3D Controlled Source Electro Magnetic (CSEM) data were postulated to be associated with the Lower Tertiary to Upper Cretaceous channel systems play. Quantitative integration of the unconstrained CSEM anomalies with all available seismic data types, indicates the resistive events are much more likely to be generated by hydrocarbon presence than by carbonate-dominated lithology. In addition, deeper anomalies observed within the Cretaceous slump/ponded fan sequence deposits similar to the Zaedyus discovery in French Guiana, were confirmed by subsequent CSEM 3D inversions. The integration of modern seismic and CSEM data has provided a powerful exploration tool for de-risking large exploration leads identified in two independent, but complimentary data sources, in this unexplored, frontier basin.